A person on the ground, such as a soldier, may need to know what is in the immediately surrounding area. Reconnaissance of an area can often be efficiently done from the air. (For example, it has been reported that tanks operating in urban environments require helicopter support before turning a street corner, to detect anti-tank weapons). However, manned aircraft are expensive, not always readily available, may not have access to the area to be looked at and a direct link to the person at the site is not always available. Satellites are only available a few times each day at predictable times, the resolution of commercial imaging satellites is not very good, and again, the ability to get the information to the person at the site is limited. Unmanned aircraft flown by the person at the site are large, expensive or difficult to operate, and require an open area for launch and recovery. Recovery is necessary because of the expense involved. Larger unmanned aircraft flown from fixed bases have many of the same problems as manned aircraft. Balloons are time consuming to inflate and fly, and depend too much on calm wind conditions.
Aircraft or satellites over-flying an area typically take vertical photographs of the earth directly below the vehicle, or panoramic photographs that extend out to either side. A large amount of ground can then be covered by flying the vehicle in a forward direction and combining the photographs into a long strip.
These methods are expensive, and not in the direct control of the person requiring the photographs, so there is an inherent time delay in getting the images to him.
Systems that are portable, and can be carried into the field, require input from the user to aim the imaging sensor at targets of interest. This is also time consuming, and involves some level of skill and practice to be able to control the imaging device accurately.
A device that loiters above the operator may also give away his position if it is detected. The chances of detection go up with time.
A lightweight, man-portable device that automatically gives the person an immediate and detailed view of the entire surrounding area, centered on his position is not available.